Poly water main grounding question

[Peter Plein]

City water main is poly. I just replaced the panel not the entire service. Must I run the ground all the way to the meter or can I just bond anywhere and jump the meter? Plus of course the Hot water heater. All water supply in the house is copper.

[Jerry Peck - Codeman]

You actually have a double question which you may not even be aware of:

1) The copper water piping system in the house: This must be "bonded" to the ground at the panel, for all intents and purposes for you, this would be the same as "grounding" that copper piping to the ground at the panel. Yes, it the water meter is between two sections of copper pipe, you must "bond" (virtually the same as "ground") around it from metal pipe to metal pipe.

2) The city water service pipe was, I presume (you did not say) previously metal, but it is now plastic. It is possible that your electrical system used the metal water service pipe as a "ground" (if it was metal), however, as the water service pipe is now plastic that will not do any good. That means that you will need to drive two ground rods, making sure they are a minimum of 6 feet apart (there is nothing wrong with them being 10-50-100 feet apart other than using more wire between them, just make sure they are *at least* 6 feet apart). This is based on the extremely limited information you have given, so I am making some presumptions, such as your only "ground" was the metal water service pipe which is now plastic.

You may actually have additional "grounds" and not need the two driven rods, but you did not provide enough information to ascertain that.

If in doubt, have a local licensed and competent electrical contractor come out to your house and verify the electrical system is properly grounded, which means they should measure the resistance to ground, and if they have the equipment for that it would be a good guess that they are indeed "competent".

[Peter Plein]

I should have been more clear. There was no water pipe bond at all. There was at one time a driven ground but has long since rotted away (seashore area). I know to drive two ground rods and I must bond the copper pipe water system (poly main) but the water meter is about 85 wire feet from the service panel. There is only about 6 inches of metal pipe on the city side of the water meter, yes I know it must be jumpered. My only question is may I bond to the water pipe system at any point or must I run back to the water meter.

[Jerry Peck - Codeman]

Hi Peter,

There was no water pipe bond at all.

Which you need to install and which may be done at any place along the metal water piping, and which is typically done closest to the electric service equipment.

There was at one time a driven ground but has long since rotted away (seashore area).

I would install two stainless steel ground rods due to the corrosive environment the ground rods are in.

There is only about 6 inches of metal pipe on the city side of the water meter, yes I know it must be jumpered.

No, that does not need to be jumpered. There is not going to be any current flow through the water meter as there is only 6" of metal pipe on the city side, so no jumper is needed.

My only question is may I bond to the water pipe system at any point or must I run back to the water meter.

Bonding the water piping may be done at any place along the metal water piping. Make sure to also bond to the metal hot water piping at the water heater as the dielectric fitting will break the electrical continuity between the metal water piping systems (between hot and cold), with that electrical continuity needing to be re-established with the bonding jumper.